Sip moderators/SIP performance pipe owners please read

Right having read about this topic numerous times on this board I reckon its time for some answers.
And the topic is, yes you’ve guessed it the SIP pipe!!
A lovely looking pipe, and lovely sounding pipe, but wheres the top end??
I purchased the following from SIP this year with the view to tuning my T5 into a rally going 70 mph crusing machine.
Mallossi 172cc kit
Mallossi reed valve kit
Cosa 21 tooth clutch
Dellorto fuel pump
SIP performance pipe
Not cheap I’m sure you’ll agree, but having read the advice in the SIP catalogue I was sure these items held the key to building a flying machine.

Now I had the engine casings milled to suit the reed valve kit, rebuilt the engine, ran it in as in the Mallossi kit instruction book.

Then this weekend I took it for a 100 mile round trip, now 1st,2nd & 3rd gear are fine but when in fourth gear it just won’t hold at a decent speed. Everytime theres a slight incline or head wind I have to knock it down into 3rd to pick up speed again.

Now what else can I do? I’ve brought the best kit, best reed valve kit & the best exhaust? Or so I thought, after following the advice in the SIP catalogue!!

Then I’ve read in another post on this site that the SIP performance pipe design has been changed! But in the catalogue it claims to have been tested and proven as the number one pipe! But on this message board the main topic seems to be its disappointing performance.

How about some advice SIP? Is there a secret to unlocking the pipes power?

I’m beginning to think I could have better performance with just the Mallossi kit and a sito plus at a fraction of the price?

Maybe your better using a UK dealer who you can phone for advice?

If anyone has any ideas to improving my performance using the kit I have please let me know, I’m thinking of using my old clutch and rebuilding it using the cosa plates to make a stronger standard clutch.

Sorry about the moaning, but there seems to be a lot of people on here having the same problems and SIP don’t seem to be giving any answers………

everyone moaning about the sip pipe on t5’s all have the cosa clutch as well.the t5 is fantastically geared as it is & it seems the cosa clutch over gears it.go back to the original t5 one which is basically the p2 one,(indestructable with the reinforced sip basket)and see how she goes,i assure you a noticeable change

They take your money and run [:dance3:]

Cheers Andy for the advice, what a disappointment that the clutchs aren’t interchangable. (as i found out this weekend)
I’ve had a band welded round my old clutch basket, but decided since i was pulling my engine about i’d treat it to a full rebuild and a gas flowed crank.
I’ll keep you posted with results once the rebuilds complete and i’m up and running again, hopefully running faster than before!!

I’m pretty sure all the Scorpion pipes are exactly the same, only the slip jointed down pipes are different for fitting onto different barrels. Looks good, sounds great, looses some top gear torque but gives top end back on the flat.

Hey Lurch: Good news.
The Scorpion is doing what you want it to do (and it is now made in the Uk :wink: .

I want a PM even more now going by your description.

Thanks for all the feedback we’re geting from you…just what I wanted to hear (given the circumstances)!

THE SIP PIPE IS THE OLD KEGRA PIPE RE-BADGED. You need to delve into the Scooter Centre catalogue to find this out officially though: it roughly says „JL Performance Based on the Old Kegra…blah blah very revvy simlar to the PM“. My powervalve is on order, I hope to get it, fit it, adjust it and get it on the Dyno @ Holiday In Holland. I’ll try and do two runs if it is not too dear…one without the valve and one with.

I’m sure SIP would remain unimpressed though…can’t get sweet FA out of them here or by email…

Kegra might confirm this as they don’t do the pipe anymore.
Slinging-dog…send it back ‚rejected‘…the worst they can do is give you a credit-note…I hope to have some diagrams you can include in the refund request…

I saw it!
Hasn’t even reached near that yet![:(]

f******* S.I.P!!!
thats the last of my money you’ll be getting, you haven’t even got the customer service to come on this site and help people who’ve spent good money with you.
I knew i should have trusted my Grandads judgement of Germans…

ok, sorry for seeing this thread only now, I must admit that we look into the english language board too rarely. Will change this for the future - promised!
Hope you don´t really believe your grandad in all what he says…

We designed last year a new version of the T5 exhausts due to complaints that it wouldn´t work perfect in some combinations. Please remember that T5 is not very popular outside of england and that we sell about 50 T5 exhausts of all kinds per year - means that it is not easy to make any profit after developping an exhaust and producing the necessary tools. Now you can have one version with better torque and less high-rpms, and one with top rpms but reduced torque in lower revs. It is all a compromise… See this: SIP T5 exhaust NT

Generally again sorry for not listening on that topic for too long. In future if there is a problem of an ignorant SIP Team please let me know at [email protected]

Judging by the number of complaints I guess the sip pipe sucks on a T5. I have one on my PX210 and have none of the problems you have experienced, I did until I changed to a T5 4th, as it would not pull 4th. So gearing may well be the answer. Taffy and others recommend the cosa clutch as it does not explode at high revs, however, a 4 plate convesion kit combined with a ring welded around the basket will also do the trick. If the old drive gear fits the cosa clutch you are in business if it doesnt try the 4 plate kit. Is the original drive gear a 20 tooth cog?

try caving in the fat part of the exhaust with a big hammer,this will make the expansion chamber smaller and wouldnt need so much throughput to fill it hence pulling better

Andy, i brought the crank as new ‚gas flowed‘ it just looks to have been polished round the cut out.
When are we going to get some answers SIP??
How many complaints do you need. Be warned you’ve had the last of my cash, how many others feel the same??

Andy,I ment the casing’s, never touched the barrel/casing but I got chiselspeed to open the head for the kit,with the old exhaust it will pull well even needing upgearing,the exhaust I got secondhand with a p200 and T5 down pipeso try it worth a go!
completly changed the bike the SIP killed it!!!

Cheers for the up-date Lurch.

I’ve come to pretty much the same conclusion as you (as you probably worked out)

I did get the SIP to ‚work‘ on the standard clutch…but only with a lot of perceverance…including using an HP4…and guess what it blew-up (melted piston).

I’m still gonna try to get the mutha to work by lengthening it. And still keep bashing at these lot.

You don’t know another mate with a PM you could borrow do you?..I’d be really interested to hear how that works.

To be honest mate you are not going to get any bad reports from the people who are selling the pipes.

The Scorpion does seem to rank well, though if I remember correctly the test you are talking about was for the P125 chamber. Are they the same as the T5 one then[?[]like at Taffys?) The SIP/JL are the only pipes that I know that are specially designed for the T5 172 capacity/rev range. We know the SIP is shit and has been improved.

IF the Scorpion is different from the Scorpion P2 chamber then it sounds like you are on to a winner…they have improved on the flaws in the SIP (and SIP are now followers in improving their design to keep-up). With the build quality reports, price and guarantee on the Scorpion (it has to have one as it carries the ‚E‘ mark) all in it’s favour.

I really hope it works out …let us know.
If you get chance, stack it against a Scorpion for a P2 and let me know if it is the same chamber, or a different one?


Did you try your mates taffy 200 pipe with your t5 downpipe?

I’ve been offered a 200 pipe and wondered if i bought a new t5 downpie from taffs, would it fit?

Are they essentially the same pipes but different headers?

Why don’t you try an old T5 exhaust, cut the down pipe off and bodge!! As for the Taffspeed, I think the pipe fits both T5 and P2 as mine had both with it. As the previous owner bought it new for P2 then put it on his T5.

After trying the JL pipe, putting back on the Taff pipe I found that the JL pipe would pull about 83mph down hill, as soon as on the flat would drop to about 70, whereas the Taff would only pull 78mph, but would maintain the speed.

Looked at P2 scorpion, it seems to have a fat chamber, JL P2 was not as fat as the scorpion but longer than the T5 JL.

Waiting to see what you lot are doing before I purchase a new pipe!!! So choose wisely!

Thanks for all the info…



If you want something that will cruise at 70mph you have to start with a P2.

How did you get to the 225 stage Dylan? what’s it like all round? what year engine is it built on? where can I get me one of those?
etc,etc,etc would very much like to hear more about the beast.

Exact same set-up and problem as Lurch (Running a taffy profile head)
The T5 is not the same as a P2 and finds it’s power differently: Trough its capacity to reach high rpm (on a short stroke).

A few things I have learnt (froom others) and found out myself.

The Mal 172 and Sip pipe both make all the power at hhigh rpms (not measured but feels like at least 6000rpm up (where a standard P2 is already revved out!)

The combination of the T5 kit and pipe + upgear means that very often in 4th you are running in that soft area before 6k rpm - this is worse than a standard engine as there is some give on the pipe (less back pressure @ low rpm) to allow for the power higher up.

You can overcome this in in a number of ways: Fine tuning: take compression up to the limit (1.2mm squish) and get your carburation set-up on the nail (ie.a slean as you dare). Go back to 20 tooth drive cog. I did this and the set up pulled like a train, even into massive head winds (until I melted the piston coz the timing was too advanced (on an HP4) .
Though the clutch had stiffer springs to stop the slip, it was not banded and expanded alarmingly: the basket is now trash.

Look at the SIP ‚classic news‘: new T5 pipe ‚longer downpipe, more torque, particularly suited to Mal & Polini kits‘…so what do you think? It’s all in the pipe: Sort that and I think all us sufferers will be able to run the 21 tooth and give all those P210/225s a good run for their money. Personally I cannot afford a new pipe and am therefore going to try and extend the downpipe on the original (SIP’s advice as allegedly the new longer one does not fit the old pipe)., do a bit of work on the barrel and try and get things working in a bit better harmony.
PS the 7 spring drive cog is NOT interchangable with the Cosa one…unfortunately



What about some input here: The performance problem of the SIP stainless on the Malossi 172 is obviously known…you have brought out a new one that performs better.

I enquired: Customer Service said that the new down pipe could not be fitted to the old chamber.

What about an ‚adaptor‘ longer down pipe and adjusted bracket to compensate then?

As the stuff is hand made it should not be too much trouble!?

You have already probably pre-sold 20 to the people on this thread if you can help solve the problem with the old pipe and Malossi kit.

I think tou owe it to us (particularly if you want to keep loyal customers)…no one is going to buy the new pipe to replace your old one.

  1. We cant re-sell the old one now the new one is out. Personally I paid 300 Euro for the pipe (i bought the kit from you at the same time). You sold it to me knowing that the new pipe was coming and that there was a problem „buy the stainless“ you said…it will last years and years…no rust .
  2. Everyone is trying chambers made by other manufacturers for the P2 and getting better results.

I would be willing to pay for a new down pipe and bracket that makes the pipe work better. Can you get one made for me/us?

Andy H…Last of the big spenders?